Wind Tunnel Test Techniques

Wind Tunnel Test Techniques
Author: Colin Britcher
Publisher: Academic Press
Total Pages: 672
Release: 2023-10-20
Genre: Technology & Engineering
ISBN: 0128181001

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Wind Tunnel Test Techniques: Design and Use at Low and High Speeds with Statistical Engineering Applications provides an up-to-date treatment of the topic. Beginning with a brief history of wind tunnels and its types and uses, the book goes on to cover subsonic, supersonic and hypersonic wind tunnel design and construction, calibration, boundary corrections, flow quality assessment, pressure surveys, and dynamic testing. It also focuses on wind tunnel facilities, making it useful for both the designer and operator. Engineers and graduate students in aerospace, automotive and similar programs will find this book useful in their work with experimental aerodynamics, gas dynamics, facility design and performance. Deals with a broad range of flow speeds in wind tunnels, from low speed to high speed Provides a discussion of similarity laws as well as material on statistical analysis Includes coverage on facility-to-facility and facility-to-CFD correlation Presents advanced topics such as cryogenic wind tunnels, ground simulation in automotive testing, and propulsion testing

Democratizing Innovation

Democratizing Innovation
Author: Eric Von Hippel
Publisher: MIT Press
Total Pages: 224
Release: 2006-02-17
Genre: Business & Economics
ISBN: 0262250179

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The process of user-centered innovation: how it can benefit both users and manufacturers and how its emergence will bring changes in business models and in public policy. Innovation is rapidly becoming democratized. Users, aided by improvements in computer and communications technology, increasingly can develop their own new products and services. These innovating users—both individuals and firms—often freely share their innovations with others, creating user-innovation communities and a rich intellectual commons. In Democratizing Innovation, Eric von Hippel looks closely at this emerging system of user-centered innovation. He explains why and when users find it profitable to develop new products and services for themselves, and why it often pays users to reveal their innovations freely for the use of all.The trend toward democratized innovation can be seen in software and information products—most notably in the free and open-source software movement—but also in physical products. Von Hippel's many examples of user innovation in action range from surgical equipment to surfboards to software security features. He shows that product and service development is concentrated among "lead users," who are ahead on marketplace trends and whose innovations are often commercially attractive. Von Hippel argues that manufacturers should redesign their innovation processes and that they should systematically seek out innovations developed by users. He points to businesses—the custom semiconductor industry is one example—that have learned to assist user-innovators by providing them with toolkits for developing new products. User innovation has a positive impact on social welfare, and von Hippel proposes that government policies, including R&D subsidies and tax credits, should be realigned to eliminate biases against it. The goal of a democratized user-centered innovation system, says von Hippel, is well worth striving for. An electronic version of this book is available under a Creative Commons license.

Design and Calibration of the Mixing Layer and Wind Tunnel

Design and Calibration of the Mixing Layer and Wind Tunnel
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
Total Pages: 36
Release: 2018-07
Genre:
ISBN: 9781722148676

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A detailed account of the design, assembly and calibration of a wind tunnel specifically designed for free-shear layer research is contained. The construction of this new facility was motivated by a strong interest in the study of plane mixing layers with varying initial and operating conditions. The Mixing Layer Wind tunnel is located in the Fluid Mechanics Laboratory at NASA Ames Research Center. The tunnel consists of two separate legs which are driven independently by centrifugal blowers connected to variable speed motors. The blower/motor combinations are sized such that one is smaller than the other, giving maximum flow speeds of about 20 and 40 m/s, respectively. The blower speeds can either be set manually or via the Microvax II computer. The two streams are allowed to merge in the test section at the sharp trailing edge of a slowly tapering splitter plate. The test section is 36 cm in the cross-stream direction, 91 cm in the spanwise direction and 366 cm in length. One test section side-wall is slotted for probe access and adjustable so that the streamwise pressure gradient may be controlled. The wind tunnel is also equipped with a computer controlled, three-dimensional traversing system which is used to investigate the flow fields with pressure and hot-wire instrumentation. The wind tunnel calibration results show that the mean flow in the test section is uniform to within plus or minus 0.25 pct and the flow angularity is less than 0.25 deg. The total streamwise free-stream turbulence intensity level is approximately 0.15 pct. Currently the wind tunnel is being used in experiments designed to study the three-dimensional structure of plane mixing layers and wakes. Bell, James H. and Mehta, Rabindra D. Unspecified Center NCC2-55...